If you read the interviews where Dario said this closely, you'll find that he's talking in hypothethicals.
We will have to wait for the S-1 to get audited figures, until then, only insiders have any idea (and only the accountants can be sure).
> SemiAnalysis estimates that Anthropic's overall gross margin has rebounded from negative 94% in 2024 to the mid-60% range, with the gross margin of its API business exceeding 80%.
https://www.tradingkey.com/analysis/stocks/us-stocks/2620181...
Given Anthropic is charging $50 per million output tokens on Fable, those high margins are very believable.
However, I find these numbers incredibly hard to believe, and most likely deceptive, given that they recently (like March) started making enterprises pay API rates, so even if they were profitable (and if they paid from Fable training from this post cost money) I would be sceptical that this will continue, given all the competition in this space.
tl;dr let's all wait for the S1 (it will presumably be soon, unless SpaceX declines get them to postpone).